Can you tow more?

Is there there anyway to increase tow power? Im talking rebuilding the rear building the rear end, better shocks, new hitch, bigger engine,load leveling kit, or anything? Right now I have a 4.3l v6 that I really like but iw increase tow to about 10000 or 12000 right now it's 8

There's a lot to this question. First, what model truck do you have? To haul 10-12k of weight, you're going to need a 1-ton class vehicle to pull it. Depending on what you have now, you can do something similar to what I did and upgrade the entire suspension and driveline to 1-ton standards, but even then you'd likely need to put in extra frame supports and box in the frame rails to get the kinda of strength and stiffness to haul 12k pounds of load.